The present invention relates generally to the field of radio transmitters and, more specifically, to portable devices used to transmit music and voice into local FM radio receivers.
A number of transmitting devices are presently available which are capable of transmitting a frequency modulated signal into local receivers, however, they all suffer from complexity and difficulty in adjusting the output frequency of the transmitter. For example, (B. Trask U.S. Pat. No. 4,021,737; R. Redfield et al. U.S. Pat. No. 3,122,847 and R. Palmer U.S. Pat. No. 3,296,916) all provide portable transmitting systems which are tuned by a rotary type capacitor. Once adjusted, their oscillator frequencies may be reset by unauthorized personnel.